Starter-generators are mounted to gas turbine engines via an auxiliary or accessory gear box housing. The accessory gear box is generally driven by a tower shaft meshing with gears on the low pressure shaft of the engine and providing gear reduced power take off for various accessories such as oil pumps, fuel pumps and the starter-generator on an exterior portion of the engine.
During manufacture, testing and routine maintenance, the starter-generator is often removed and reinstalled. The starter-generator conventionally is an electro magnetic machine with a drive shaft extending out the end mounted to the accessory gear box with a splined shaft surface to engage the gear drive mechanism of the accessory gear box. The starter-generator also includes air cooling with an air inlet usually at an end opposite to the mounted end of the starter-generator such that cooling air passes through to remove excess heat. Air is exhausted with fans out of the opposite mounting end adjacent to the connection of the starter-generator to the accessory housing.
Substantial heat is produced by the starter-generator which must be dissipated by the unit's cooling air flow. The cooling air flow, in a conventional V-band held starter-generator installation, is discharged overboard through a separately located scroll air duct. Conventional installations additionally mount a scroll or collector either axially in line with the starter-generator or radially outward from the starter-generator.
Also, conventionally, the starter-generator is mounted to the accessory gear box with mating flanges that are secured with a V-band clamp that encircles the flanges and provides a quick release and detachment method. The starter-generator has a connecting flange which mates with the connecting flange of the accessory gear box usually having a beveled flange rear face and planar forward face to abut the planar face of the mating flange. The V-band groove engages the beveled rear surfaces of both abutting flanges and when tightened with a clamp mechanism, a wedging action on the interlocking beveled or sloped faces occurs to ensure a tight connection and a liquid impervious seal.
It is an object of the invention to improve upon conventional starter-generator (S/G) mounting systems to include quick release and quick install means for collecting and exhausting the S/G cooling air that is emitted from the starter-generator.
It is a further object of the invention to provide a means to collect exhausted cooling air while maintaining the starter-generator mounting system as a compact and quickly operated system due to the numerous maintenance activities that require removal and installation.
Further objects of the invention will be apparent from review of the disclosure, drawings and description of the invention below.